If you have E153u-1, E153u-3, E173u-1 devices with unsupported for unlock firmware version, you can re-flash your device with unlockable firmware from the support area and then perform unlock procedure. Not all devices can be re-flashed!

Write Firmware feature is available only for Octopus/Medusa card owners (Octopus/Medusa box should be connected to your PC).